Infrared (IR) photography is a fun little side project of mine that I do from time to time. No, I don't have any fancy equipment, like an IR converted camera, or anything like that. For me, IR photography is a natural extension of my love for long exposures.
Long exposure usually refers to any exposure over 5-10 seconds in length. A long exposure is one way to have a still photograph show motion. An image can have the blur of a train going by, or the ghostly blurs of people walking, or the smooth streaks of clouds blowing overhead. My Lee Filters Big Stopper is my filter of choice for visible light long exposures.
I use a Hoya R72 filter for my infrared images; it simply acts as a bandpass filter around 720nm, which is one frequency in the IR spectrum. Images with this filter are long exposures on my camera because I have not removed the hot mirror filter in front of my 6D's image sensor. Most modern digital cameras have several filters integrated into the sensor assembly, including one that blocks UV and IR light. Basically, this filter allows IR light through, and the camera blocks most IR light. Exposures are in the 30s ballpark to capture enough light. The light is primarily captured on the red photo receptors, so the image will primarily look red, when viewed without any editing, like the image below.
IR photographs also appear different than visible light photographs. Certain objects are more IR reflective than others, such as clouds and leaves. Leaves will often appear bright white, and skies will appear dark, almost black.
The IR photographs I take lend themselves well to black and white conversions. For example, the above image became the below image. The only changes are:
- convert to black and white
- increase contrast
- increase clarity
- increase sharpening
- change tone curve to medium contrast
I can also do fun things like taking two exposures, one in color, one in infrared, and overlay them. This gives me something like the image below, which is certainly neat, and benefits from the sharp contrast between the colors.